same problem with the lock screen.

Can you attach screenshots that show the things that you see which are not the things that you're expecting to see?

Sorry i made an error in "expected result"

EXPECTED RESULT

the fingerprint dialog is displayed instead of the password dialog

How to take a screenshot of the lock screen ?

Your phone? But you can take a screenshot of the other thing with Spectacle.

With my smartphone when I activated the fingerprint reader authentication then password field was no more displayed.
The password field is displayed :
- if there is too many fails about fingerprint reading
- after 7 days of using the fingerprint authentication according to not forget the password.

Displaying the password field when you activated the fingerprint authentication is confusing. You must display nothing or just a message saying "please touch the fingerprint to unlock"

Screenshots please

Created attachment 151520 [details]
lock screen

You can see that the password field is displayed by default even if you activated the fingerprint authentication.

same problem with login screen

The login screen doesn't have fingerprint support yet, so that's expected.

Your screenshot depicts the lock screen without fingerprint support enabled, or with it not working. If it was working, there would be text saying something like "Swipe your [finger] on the fingerprint reader" above the password field. So it looks like there's a bug here, rather than a design choice.

Are you saying that you *never* see the "Swipe your [finger] on the fingerprint reader" text anywhere?

I confirm the capture of the lock screen. There is only a message saying "swipe ..." if you click on ">". By default, there is a password field.

sddm file contents :

#%PAM-1.0
auth    [success=1 new_authtok_reqd=1 default=ignore]   pam_unix.so try_first_pass likeauth nullok
auth    sufficient      pam_fprintd.so
auth     include        common-auth
account  include        common-account
password include        common-password
session  required       pam_loginuid.so
session  include        common-session
session  optional       pam_keyinit.so revoke force


kde file contents :

auth 			sufficient  	pam_unix.so try_first_pass likeauth nullok
auth 			sufficient  	pam_fprintd.so

>> Are you saying that you *never* see the "Swipe your [finger] on the fingerprint reader" text anywhere?

No

On login screen and lock screen you must click on ">" to launch fingerprint dialog.

Can you attach a screenshot of what you see when you click on the > button on the lock screen?

Created attachment 151572 [details]
a screenshot of what you see when you click on the > button on the lock screen?

Thanks. Re-titling.

I can confirm this issue as this has happened sporadically to me. It's not 100% reproducible though.

If I understand well the chapter "Using a fingerprint reader" here https://wiki.archlinux.org/title/SDDM#Using_a_fingerprint_reader
then it is normal to expect to get first the password field, then by typing "enter" with an empty password field to get the fprint dialog.

If I sum up :

to get only fprint dialog you add in sddm file 

auth 			sufficient  	pam_fprintd.so

to get password field then fprint dialog you add in sddm file

auth 			[success=1 new_authtok_reqd=1 default=ignore]  	pam_unix.so try_first_pass likeauth nullok
auth 			sufficient  	pam_fprintd.so

What do we add to get fprint dialog then password field dialog as a backup ?

Is this about klockscreen or about SDDM / display manager?

sddm login and lock screen